trillion

noun

tril·​lion ˈtri(l)-yən 

1

: a number equal to 1,000 times one billion see Table of Numbers

2

: an indeterminately large number

a trillion mosquitoes out tonight

trillion adjective

trillionth

ˈtri(l)-yən(t)th 

adjective or noun

Examples of trillion in a Sentence

Recent Examples on the Web

The gut microbiome consists of trillions of bacteria, viruses and other microbes that populate human intestines. — Brenda Goodman, CNN Money, 1 Oct. 2026

Areas such as the Clarion-Clipperton Zone in the North Pacific between Hawaii and Mexico, the central Indian Ocean basin, and the Penrhyn basin in the South Pacific are studded with trillions of stones containing critical minerals. — Michael Albertus, Foreign Affairs, 30 Sep. 2026

After decades of decline, this president is restoring America's industrial competitiveness and securing trillions of dollars in new investment. — Kathryn Watson, CBS News, 28 Sep. 2026

Because of the trillions of dollars to be spent on deploying upgrades to the grid, electricity prices are continually rising, Patti said. — Eric Rosenbaum, CNBC, 25 Sep. 2026

Word History

Etymology

French, from tri- + -illion (as in million)

First Known Use

1745, in the meaning defined at sense 2

Rhymes for trillion

• billion
• million
• pillion
• castilian
• civilian
• cotillion
• pavilion
• postilion
• quadrillion
• reptilian
• vermilion
• vermillion

Kids Definition

trillion

noun

tril·​lion ˈtril-yən 

1

: a number equal to 1,000 times one billion see number

2

: a very large number

a trillion mosquitoes out tonight

trillion adjective

trillionth

-yən(t)th 

adjective

trillionth noun